The content described in this section merely provides background information regarding embodiments, and does not constitute the prior art.
A wearable display device, such as, for example, a head-mounted display (HMD), is a device that is devised to let a pilot know flight information including, for example, the altitude and speed of an airplane. General commercial products were invented in the 1990s, and commercialized products have received great attention since 1997.
A wearable display device is a device that is worn on the head, like a pair of glasses, so that an enlarged image is formed in front of the user's eyes so as to allow the user to view the image, and a display having a size of 1 inch or less is generally used therein, but the user can perceive an enlarged screen approaching 100 times the actual size through the application of high-grade optical technology.
The growth of the wearable computing industry is expected due to the technical development and commercialization of peripheral appliances such as wearable display devices. Although current wearable display devices have mainly been developed for the enjoyment of movies or games, owing to the higher performance and smaller size of computer systems and to the rapid development of display apparatuses, which are exemplified by LCDs and LEDs, and of image communication technology, wearable display devices have recently been studied and developed for use as wearable monitors, and commercialized products based thereon have been launched.
Although the wearable display device market has encountered difficulty in the past due to relatively high prices, it is expected that the market will rapidly grow along with the wearable computer industry. The application fields of wearable display devices are expected to expand to industrial sites, sites for the maintenance of bulky products such as, for example, cars, airplanes, and ships, and warehouses, as well as to sports entertainment, such as car racing.
In particular, the development of processor and software technologies enables a reduction in the size of computing apparatuses, and wearable display devices are expected to be developed for use in personal-computing apparatuses, such as smart phones, rather than serving as a device that merely displays an image.
In the wearable display device, the light that is transmitted to the user's eyeball follows a predetermined path, and the performance of the product is determined by stable maintenance of the path of the light. In the process of assembling various components to manufacture the wearable display device, a prism, through which light passes at a final step in order to be introduced into the user's eyeball, is coupled to a base; however, the prism may undesirably move relative to the base without being securely coupled to the base.
If the prism moves relative to the base, the path of light does not remain stable, which may cause deterioration in the quality of the wearable display device.
In order to solve this problem, the base and the prism may be securely coupled to each other using an adhesive material; however, there is a concern that the adhesive material may flow down and contaminate the wearable display device and therefore may deteriorate the operational performance and the image quality. Further, because an adhesive material does not provide sufficient coupling strength for the components, there is still a problem in that the prism may move relative to the base.
In the process of assembling various components to manufacture the wearable display device, a prism, through which light passes at a final step in order to be introduced into the user's eyeball, may include a plurality of sub-prisms, which may be coupled to each other using an adhesive agent.
If the adhesive agent flows down to regions other than the regions of the sub-prisms that are bonded to each other by the adhesive agent, this may have a negative influence on the light that passes through the prism, which may result in deterioration of the performance of the wearable display device.
When various components of the wearable display device are coupled to each other, the components, through which light passes, need to be securely coupled to each other in order to prevent the light from being distorted by shaking.